---
title: "malformed"
description: "Authentication credentials were incorrectly formatted"
---

<Danger>`err:unkey:authentication:malformed`</Danger>


```json Example
{
  "meta": {
    "requestId": "req_2c9a0jf23l4k567"
  },
  "error": {
    "detail": "Authentication credentials were incorrectly formatted",
    "status": 401,
    "title": "Unauthorized",
    "type": "https://unkey.com/docs/api-reference/errors-v2/unkey/authentication/malformed"
  }
}
```

## What Happened?

This error occurs when your request includes authentication credentials, but they are not formatted correctly. The Unkey API expects API keys to be provided in a specific format in the Authorization header.

Common causes include:
- Missing the "Bearer" prefix before your API key
- Including extra spaces or characters
- Using incorrect casing (e.g., "bearer" instead of "Bearer")
- Providing a malformed or truncated API key

Here's an example of a request with incorrectly formatted credentials:

```bash
# Missing the "Bearer" prefix
curl -X POST https://api.unkey.com/v2/keys.listKeys \
  -H "Content-Type: application/json" \
  -H "Authorization: unkey_YOUR_API_KEY"
```

## How To Fix

To fix this error, ensure your Authorization header follows the correct format:

1. **Use the correct format**: Ensure your Authorization header follows the format `Bearer unkey_YOUR_API_KEY`
2. **Check for extra spaces or characters**: Make sure there are no invisible characters or line breaks
3. **Verify the API key format**: Your Unkey API key should start with `unkey_`

Here's the correctly formatted request:

```bash
curl -X POST https://api.unkey.com/v2/keys.listKeys \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer unkey_YOUR_API_KEY"
```

When properly authenticated, you'll receive a successful response like this:

```json
{
  "meta": {
    "requestId": "req_8f7g6h5j4k3l2m1n"
  },
  "data": {
    "keys": [
      {
        "keyId": "key_123abc456def",
        "name": "Production API Key"
      }
    ]
  }
}
```

## Common Mistakes

- **Authorization header format**: Must be exactly `Bearer unkey_YOUR_API_KEY` with a single space after "Bearer"
- **Incorrect casing**: Using "bearer" instead of "Bearer"
- **API key format**: Your Unkey API key should start with `unkey_` and contain no spaces
- **Using wrong key type**: Ensure you're using a root key for management API calls
- **Copying errors**: Check for invisible characters or line breaks that might have been copied
- **Extra characters**: Including quotes or other characters around the API key
- **Truncated keys**: Accidentally cutting off part of the API key when copying

## Related Errors
- [err:unkey:authentication:missing](./missing) - When no authentication credentials are provided
- [err:unkey:authentication:key_not_found](./key_not_found) - When the provided API key doesn't exist
